Sheath flow device and hematology analyzer

Abstract

An embodiment of a sheath flow device may include: a reflecting plane, aspheric reflecting surface, and a conduit for passage of cells disposed in a central hollow. A focal point of the aspheric reflecting surface is positioned in a location where cells settle. A collimated beam generated by an external light source incident on a first reflective side of the reflecting plane, is reflected to reach a first reflective surface of the aspheric reflecting surface, and reflected before being focused on the focal point, after which the light proceeds to reach a second reflective surface of the aspheric reflecting surface to be reflected to reach a second reflective side of the reflecting plane to emerge after being reflected thereby. The first and second reflective sides and the first and second reflective surfaces may be centrosymmetric. The sheath flow device improves the alignment accuracy of beam commissioning during the application process.

What is claimed is: 
     
       1. A sheath flow device, comprising:
 a reflecting plane; 
 an aspheric reflecting surface comprising a focal point; 
 a conduit comprising a central hollow and configured to allow passage of cells disposed in the central hollow; and 
 a transmission plane adjoining the reflecting plane, the transmission plane configured such that: 
 a parallel light vertically incident on a first transmissive side of the transmission plane is transmitted thereby to reach the first reflective side of the reflecting plane, reflected thereby to reach the first reflective surface of the aspheric reflecting surface, and reflected thereby before being focused on the focal point to reach the second reflective surface of the aspheric reflecting surface to be reflected thereby to reach the second reflective side of the reflecting plane, and to be reflected thereby to reach a second transmissive side of the transmission plane to be transmitted; and 
 wherein the first and second transmissive sides of the transmission plane, the first and second reflective sides of the reflecting plane, and the first and second reflective surfaces of the aspheric reflecting surface are centrosymmetric, 
 wherein: 
 the focal point of the aspheric reflecting surface is positioned in a location where the cells settle; 
 the reflecting plane and the aspheric reflecting surface are configured such that a collimated beam generated by an external light source incident on a first reflective side of the reflecting plane is reflected thereby to reach a first reflective surface of the aspheric reflecting surface, and is reflected thereby before being focused on the focal point to reach a second reflective surface of the aspheric reflecting surface to be reflected thereby to reach a second reflective side of the reflecting plane to emerge after being reflected thereby; and 
 the first and second reflective sides of the reflecting plane and the first and second reflective surfaces of the aspheric reflecting surface are centrosymmetric. 
 
     
     
       2. The sheath flow device of  claim 1 , wherein the aspheric reflecting surface is a rotating parabolic surface. 
     
     
       3. The sheath flow device of  claim 1 , wherein an angle between the first transmissive side and the first reflective side is 45 degrees, and wherein an angle between the second transmissive side and the second reflective side is 45 degrees. 
     
     
       4. The sheath flow device of  claim 1 , wherein the reflecting plane is a total reflecting plane. 
     
     
       5. The sheath flow device of  claim 1 , wherein the aspheric reflecting surface is coated with an optical reflective film. 
     
     
       6. The sheath flow device of  claim 1 , wherein the transmission plane, the reflecting plane, the aspheric reflecting surface, and the conduit are made of a same optical material. 
     
     
       7. The sheath flow device of  claim 1 , wherein the transmission plane is coated with an anti-reflection film. 
     
     
       8. The sheath flow device of  claim 1 , wherein the reflecting plane, the aspheric reflecting surface, and the conduit are an integrally formed structure. 
     
     
       9. The sheath flow device of  claim 1 , wherein the reflecting plane, the aspheric reflecting surface, the transmission plane, and the conduit are an integrally formed structure. 
     
     
       10. A hematology analyzer, comprising:
 a light source; 
 an emitting optical system; 
 a receiving optical system; 
 a detector; and 
 a sheath flow device comprising: 
 a reflecting plane; 
 an aspheric reflecting surface comprising a focal point; 
 a conduit comprising a central hollow and configured to allow passage of blood cells disposed in the central hollow, 
 wherein: 
 the focal point of the aspheric reflecting surface is positioned in a location where the blood cells settle; 
 the reflecting plane and the aspheric reflecting surface are configured such that a collimated beam generated by an external light source incident on a first reflective side of the reflecting plane is reflected thereby to reach a first reflective surface of the aspheric reflecting surface, and is reflected thereby before being focused on the focal point to reach a second reflective surface of the aspheric reflecting surface to be reflected thereby to reach a second reflective side of the reflecting plane to emerge after being reflected thereby; and 
 the first and second reflective sides of the reflecting plane and the first and second reflective surfaces of the aspheric reflecting surface are centrosymmetric; and 
 a transmission plane adjoining the reflecting plane, the transmission plane configured such that: 
 a parallel light vertically incident on a first transmissive side of the transmission plane is transmitted thereby to reach the first reflective side of the reflecting plane, reflected thereby to reach the first reflective surface of the aspheric reflecting surface, and reflected thereby before being focused on the focal point to reach the second reflective surface of the aspheric reflecting surface to be reflected thereby to reach the second reflective side of the reflecting plane, and to be reflected thereby to reach a second transmissive side of the transmission plane to be transmitted; and 
 wherein the first and second transmissive sides of the transmission plane, the first and second reflective sides of the reflecting plane, and the first and second reflective surfaces of the aspheric reflecting surface are centrosymmetric, 
 wherein a parallel light generated by the light source is collimated by the emitting optical system before entering the sheath flow device to be focused on a position where blood cells are located therein; and 
 wherein a light transmitted or scattered by the blood cells is received by the receiving optical system and output to the detector, which carries out blood analysis based on the transmitted or scattered light. 
 
     
     
       11. The hematology analyzer of  claim 10 , wherein the light source comprises a laser, a halogen lamp or a light-emitting diode. 
     
     
       12. The hematology analyzer of  claim 10 , wherein the emitting optical system comprises a single collimating lens. 
     
     
       13. The hematology analyzer of  claim 10 , wherein the receiving optical system comprises a single collimating lens.